In the field of semiconductor devices, an anti-fuse circuit that is normally in an insulated state and that is rendered electrically conductive when a high voltage is applied thereto in order to destruct the state of insulation during the write process, has been in use. With the anti-fuse circuit, since programming is by destructing the state of insulation, writing may be made only once, and data once written cannot be erased or otherwise restored to the original state. However, as compared to other non-volatile programming elements, the anti-fuse circuit has only low on-resistance. The anti-fuse circuit thus has come to be used extensively as a non-volatile programmable circuit for a field-programmable gate array or other semiconductor devices.
Laser fuses are routinely used for a circuit that specifies addresses for substitution by a redundancy circuit for relieving failed bits of semiconductor memories, or for a trimming circuit. However, if once the semiconductor device is assembled in a package, the laser fuses cannot be programmed. Conversely, the anti-fuse circuit can be electrically programmed. The anti-fuse circuit is attracting attention because it can be programmed even if a semiconductor device is once assembled in a package.
In Patent Document 1, there is disclosed a semiconductor device that provided with a conventional anti-fuse element, and that is used in a semiconductor memory, for example. In particular, FIG. 3 of Patent Document 1 shows a semiconductor device in which, in programming an anti-fuse element 32, a high voltage (vpgm) is applied to one end of the anti-fuse element, and in which the opposite end of the anti-fuse element is connected via an N-channel protective transistor 34 and an N-channel driver transistor 38 to the ground potential GND. A voltage applied to the gate of the N-channel driver transistor 38, selected by an address, for example, is used for programming whether or not the anti-fuse element is to be in an insulation destructed state. FIG. 13 of Patent Document 1 shows a semiconductor device in which a high voltage (vpgm) is applied to one end of the anti-fuse element 102, and in which the opposite end of the anti-fuse element is connected to a VCC potential via a P-channel protective transistor 104 and a P-channel driver transistor 108. A voltage applied to the gate of the P-channel driver transistor 108, selected by an address, for example, is used for programming whether or not the anti-fuse element is to be in an insulation destructed state. [Patent Document 1] JP Patent Kokai Publication No. JP-P2002-134620A, which corresponds to US Patent Application Publication No. US2002/0051399A1